Valveless pump

ABSTRACT

The invention relates to a pump which comprises a tube ( 4 ) through which a fluid is delivered, and a device ( 2 ) for producing transverse oscillations in the fluid. On the inlet side ( 5 ), the tube ( 4 ) has a first section ( 1 ) with an invariable delivery cross-section and on the outlet side ( 6 ) a second section ( 3 ) with a variable delivery cross-section. The inventive pump functions according to the following principle: the fluid, when induced to oscillate, performs transverse oscillations in the second section ( 3 ) with the variable delivery cross-section and can thereby expand or flow in said oscillating system, while in the first section ( 1 ) with the invariable delivery cross-section the fluid oscillates not at all or only to a much lesser extent depending on the compressibility of the medium. The waves caused by the oscillation produced in the fluid therefore substantially expand in the direction of the second section ( 3 ) with the variable delivery cross-section so that the fluid inevitably flows from the first section ( 1 ) to the second section ( 3 ).

The invention relates to a pump with a pipe through which fluid isconveyed, the pipe on the inlet side having a first segment with adelivery cross section which cannot be changed, and with a means forproducing transverse oscillations in the fluid.

In pumps the fluid to be delivered is conventionally conveyed viatranslationally moved parts, for example, pistons, or rotationallymoving pump wheels. Pumping fluids by displacement of the fluid in adeformable tube, for example by squeezing the tube together, is alsoknown.

These known pumps except for the latter type of pump have thedisadvantage that in the area of the fluid to be conveyed wear phenomenaand possibly contamination of the fluid arise due to the componentssliding against one another, or seal problems must be solved. Nor is iteasily possible to convey for example sludges with coarse portions, forexample, stones, by rotating parts or valves.

U.S. Pat. No. 2,888,877 and DE 956 020 C disclose pumps which on theinlet side have a rigid pipe. Furthermore there are pump devices. InU.S. Pat. No. 2,888,877 this is a sine wave-shaped element and in DE 956020 C a piston or an elastic pipe piece which can be squeezed together.In U.S. Pat. No. 2,888,877 the pump action takes place by the crosssection of the pipe always being closed at one point by the sinewave-shaped element and repeated, progressive motion of this pointproducing the pump action. In DE 956 020 C the pump action takes placeby different friction resistances and inertial forces in the two pipesections with different diameters.

WO 00/62838 A2 describes a pump in which on either side of a middlesegment in which the pump action is produced by the external action of aforce there are elastically deformable pipe or tube sections. The variedelasticity behavior of these two segments results in different pressuresin these segments so that in the elastic contraction of the two segmentspump action in one direction or the other takes place. On either side,any, i.e. both rigid and also elastic pipes, can be connected to the twoelastic segments.

Therefore the object of the invention is to make available a pump whichavoids the described disadvantages as much as possible.

This object is achieved with a pump with the features of claim 1.

The pump as claimed in the invention works according to the principlethat the fluid, when it is caused to oscillate, can execute transverseoscillations in the second segment with the variable delivery crosssection and in this way can flow or propagate in this oscillatorysystem, conversely in the first section with the delivery cross sectionwhich cannot be changed an oscillation does not take place depending onthe compressibility of the medium or does take place only to a muchsmaller extent. The waves of the oscillation produced in the fluid willpropagate therefore largely in the direction of the second segment withthe variable delivery cross section so that flow of the fluid from thefirst segment to the second segment necessarily occurs.

The means for producing oscillations in the fluid is ideally locatedroughly in the connecting area of the first segment to the secondsegment, there being several possibilities for producing oscillations inthe fluid. If especially high demands are not imposed on the purity ofthe fluid, it becomes possible to use parts which can be moved relativeto one another, such as pistons, pipe segments which can movetelescopically, or the like. If this assumption does not apply, itbecomes possible to induce the fluid to oscillations for example by apiston which acts from the outside on a for example elasticallydeformable segment of the pipe or a means which widens or narrows thepipe cross section annularly.

With respect to the variable delivery cross section on the one hand itis possible to be able to change the delivery cross section of thesecond segment to the outside; this for example is the case for hoses orpipes with an elastically expandable wall or an elastically deformablewall section. But it is also possible to change the delivery crosssection within the pipe by for example a deformable insert locatedwithin the pipe.

One preferred embodiment of the invention is characterized in that thedelivery cross section of the second segment has partial cross sectionswith a delivery cross section which can be changed. The overall crosssection of the second segment can be invariable in any cross sectionalplane, but the delivery cross section of the partial cross sections canbe changed such that the sum of the variable partial cross sections ineach cross sectional plane always yields the invariable overall crosssection in this cross sectional plane.

Preferred embodiments are the subject matter of the dependent claims.

Other features and advantages of the invention result from the followingdescription of embodiments of the invention with reference to thedrawings.

FIG. 1 shows a schematic through a first embodiment of the invention,

FIG. 2 shows a side view of the embodiment as shown in FIG. 1,

FIG. 3 shows an overhead view of the embodiment from FIG. 2,

FIG. 4 shows a view in the lengthwise direction of the embodiment fromFIG. 3,

FIGS. 5 through 9 schematically show other preferred embodiments of theinventions,

FIGS. 10 and 11 schematically show the use of the pump as claimed in theinvention as a drive, for example for ships, in a side view and anoverhead view and

FIGS. 12 and 13 shows other embodiments of the invention.

FIGS. 1 to 4 show a first preferred embodiment of a pump as claimed inthe invention which consists essentially of a pipe 4 with a firstsegment 1 with an invariable delivery cross section and a second segment3 with a variable delivery cross section. The wall of the pipe 4 has anability to change shape under pressure or the action of oscillations,which ability is negligible within the framework of the invention, butif necessary it can be flexible, as is known for example of hydraulichoses.

The total cross section of the pipe 4 is, as is shown best in FIGS. 1and 4, divided into partial cross sections 4 a, 4 b. This subdivisiontakes place in the first segment by a rigid partition 7. This rigidpartition 7 passes into an elastic membrane at 8. This membrane 9 isacted upon by a means 2 for producing oscillations which has a pressureplate 10 which is attached to the membrane 9, and a piston rod 11 or thelike which is driven by any suitable drive means. By moving the pressureplate 10 back and forth the membrane 9 which is attached at 8 and at thepipe outlet is caused to oscillate, as is shown schematically in FIG. 1.The end can also be free. The membrane need be suspended only on atleast two sides. The oscillation of the membrane 9 furthermore changesthe delivery cross section of the partial cross sections 4 a, 4 b, inany case the overall cross section of the pipe 4 remaining unchanged.

Since the waves or vibrations are moved essentially only in thedirection of the outlet 6 through the elastic membrane 9, since thefirst segment 1 of the pipe 4 does not allow significant oscillation ofessentially incompressible fluids, flow necessarily arises in thedirection of the arrows 12 from the inlet 5 to the outlet 6 of the pipe4.

Depending on the type of medium to be delivered, the membrane 9 can beeither a thin elastic membrane, but also a link chain composed of stableand wearproof plates, when for example fluids with contents whichgreatly promote wear such as sludge or rubble are to be conveyed.

If necessary, after the outlet 6 a rigid plate or extension can beconnected to the membrane 9 in order to prevent as much as possible flowaround the edge of the membrane 9 at the outlet 6; this could reduce theefficiency of the pump as claimed in the invention.

FIG. 5 shows another embodiment of the pump as claimed in the inventionin which the pipe 4 in turn has a first segment 1 with an essentiallyrigid or compression-proof pipe or hose. The second segment 3 consistsof a double-walled pipe, the outer pipe wall 13 being rigid, converselythe inner pipe wall 4 being elastic. In the connection area of thesecond segment 3 to the first segment 1 there is in turn a means 2 forproducing the oscillations which can consist of a means which is notdetailed and which produces oscillations in the fluid. This can beeither a means which as is shown by the arrow 15mechanically-elastically deforms the transition area, for example viaplungers which press on the outside pipe 13 which is elastic in thiscase. Alternatively it is also possible to pressurize the doubled pipein the transition area, for example with a pressure sleeve, so that theinside wall 14 in the transition area is pressed periodically to theinside and the fluid is thus displaced into this area so that theoscillation of the inside wall 14 of the pipe, which oscillation issymbolized by the broken line in FIG. 5, is formed.

In the embodiment shown in FIG. 6 the variable delivery cross section ofthe second segment 3 is formed by a closed, deformable insert 16 beinglocated within the rigid outside pipe 13 and being filled for examplewith air or another compressible medium. The pipe end of the firstsegment 1 is held concentrically in the pipe 13, between the pipe 1 ofthe first segment and the pipe 13 an annular gap being formed in which asleeve 25 is sealed and supported to be movable. By axially moving thesleeve 25 in the direction of the double arrows 17 in the fluid anoscillation is in turn produced which causes delivery of fluid from theinlet 5 to the outlet 6 of the pipe 4.

In the embodiment shown in FIG. 7 the pipe of the second segment iselastically deformable, in any case in the transition area to thesection 1 it has a widening 18 which is rigid. In this widening 18 thepipe end of the first segment is concentrically held. The pipe end ofthe first segment furthermore in the transition area within the sleeve18 has an enlarged wall thickness 1 so that upon relative motion of thefirst segment 1 and the second segment 3 pump motion occurs which inturn causes oscillations in the fluid and subsequently the induced fluidflow from the inlet 5 to the outlet 6.

In the simplified embodiment as shown in FIG. 8 the rigid first segmentwith an invariable delivery cross section is connected to a secondsegment 3 with a variable delivery cross section. The pipe 4 could forexample have a square, rectangular or elliptical cross sectional shape,one wall, in the embodiment the upper wall of the second segment, beingmade to be elastically deformable. When a mechanical force is actingperiodically on this wall cross section from the outside, as is shownsymbolically by the double arrow 19, an oscillation in the fluid andthus a pump action are in turn produced.

FIG. 9 shows an embodiment in which between the first segment 1 and thesecond segment 3 a type of piston pump 23 is connected which producesthe oscillation in the second segment 3 which in turn is made as anelastic pipe.

FIG. 12 shows an embodiment in which a plate 10 with which theoscillations are produced according to FIG. 1 is not located in themembrane 9, but in the rigid partition 7, and can be moved by means of apiston rod 11 or the like transversely to the lengthwise extension ofthe pipe.

FIG. 13 finally shows an embodiment of the invention in which plates 24are movably located on opposing sides of the pipe 3. These plates aremoved synchronously such that the lower plate 24 and the upper plate 24move simultaneously and jointly up and down, by which in the fluid acorresponding flow or oscillation is produced which also is transmittedto the membrane 9.

FIGS. 10 and 11 show a pump as claimed in the invention in the form of apipe 4 in a side view and an overhead view; the pipe is attached to thehull 21 of a ship via a holding device 20. The holding device 20 is usedon the one hand to swivel the pipe 4, as is indicated in FIG. 11 by thearrow 22, and on the other hand to carry out the technically necessarymeans for producing the oscillations in the fluid. The pump actionproduces a fluid flow from the inlet 5 to the outlet 6 which of coursecauses the opposite motion of the ship.

As is apparent from the statements above and in conjunction with theattached drawings, it is important to the operation of the pump asclaimed in the invention that one segment of the pipe has a deliverycross section which cannot be changed so that in it the oscillationsproduced in the fluid do not continue or do so only to a smaller extentthan in the second segment with a variable delivery cross section inwhich transverse vibrations of the fluid are allowed. In this way theoscillations which run back and forth in the second segment in thelengthwise direction of the pipe are essentially reflected on the firstsegment (due to the inertia of the fluid and rigidity of the firstsegment) so that overall a flow in the pipe 4 occurs which flows fromthe inlet 5 to the outlet 6. If it cannot be avoided in the area of theoutlet 6, especially for pipes with elastic outside walls, that it isclamped there and therefore there is also a short area there in whichthe delivery cross section cannot change, this does not contradict theidea of the invention if this section is so short that the oscillationor flow is not hindered to the extent as occurs through the firstsegment of the pipe.

It is important that the oscillation takes place in the vicinity of theabutting of the first and the second segment.

By suitable matching of the lengths and the delivery cross sections ofthe first and the second segment (the overall cross section of the firstsegment need not necessarily be the same size as the overall crosssection of the second segment) and the frequency with which theoscillation is produced in the fluid, and the elasticity or the shapechanging behavior of the second segment, the delivery behavior of thepump can be matched very well to the respective requirements. It is alsopossible to divide the overall cross section of the second segment notonly into two, but also into several partial cross sections, by suitableexcitation of the fluid in the individual partial cross sections almostpulse-free flow can be achieved. It is also possible to attach one ormore lowpass elements following the outlet 6 in order to smooth thefluid flow. The use of higher oscillation frequencies likewise benefitsthe smoothing of the fluid flow.

Moreover, in the invention there is hardly any danger of injuries bymechanically moving parts; this makes the invention attractive forexample as a drive for rescue boats. If the generated pressurefluctuations are not too large, water animals, such as fish and marinemammals, can be pumped without injury. It is also found that mostconstructions are very invulnerable to dirt and wear, and pumping forexample with sludge- and rock-contaminated water is possible withoutdamaging or clogging the pump.

It is also possible to convey gases by suitable dimensioning andadjustment of the pump.

In summary one embodiment of the invention can be described as follows:

A pump has a pipe 4 by which a fluid is conveyed, and a means 2 forproducing transverse oscillations in a fluid. The pipe 4 on theinlet-side 5 has a first segment 1 with an invariable delivery crosssection and on the outlet side 6 a second segment 3 with a variabledelivery cross section.

The pump as claimed in the invention works according to the principlethat the fluid when it is caused to oscillate in the second segment 3with the variable delivery cross section can execute transverseoscillations and can propagate or flow in this way in this oscillatorysystem, conversely in the first segment 1 with an invariable deliverycross section an oscillation does not take place depending on thecompressibility of the medium or takes place only to a much lesserextent. The waves in the oscillation produced in the fluid thereforewill propagate largely in the direction of the second segment 3 with thevariable delivery cross section so that flow of the fluid from the firstsegment 1 to the second segment 3 necessarily occurs.

1. Pump with a pipe (4) through which fluid is conveyed, the pipe (4) onthe inlet side (5) having a first segment (1) with a delivery crosssection which cannot be changed, and with a means (2) for producingtransverse oscillations in the fluid, wherein the pipe (4) on the outletside (6) has a second segment (3) with a variable delivery crosssection.
 2. Pump as claimed in claim 1, wherein the delivery crosssection of the second segment (3) has partial cross sections (3 a, 3 b)with a delivery cross section which can be changed.
 3. Pump as claimedin claim 2, wherein the overall cross section of the second segment (3)cannot be changed and wherein the sum of the variable partial crosssections (3 a, 3 b) in each cross sectional plane yields the overallcross section.
 4. Pump as claimed in claim 1, wherein the second segment(3) has at least one membrane (9) which extends in the lengthwisedirection of the pipe (4).
 5. Pump as claimed in claim 2, wherein themembrane (9) divides the second segment (3) of the pipe into partialcross sections (3 a, 3 b).
 6. Pump as claimed in claim 4, wherein anextension (7) of the membrane (9) extends as a rigid part into the firstsegment (1).
 7. Pump as claimed in claim 1, wherein in the secondsegment (3) there is an internal deformable pipe.
 8. Pump as claimed inclaim 1, wherein the second section has a deformable pipe wall.
 9. Pumpas claimed in claim 1, wherein the second segment has a deformableinsert (16).
 10. Pump as claimed in claim 1, wherein the means (2) forproducing oscillations is located roughly in the connecting area of thefirst segment (1) to the second segment (3).
 11. Pump as claimed inclaim 1, wherein the means (2) for producing oscillations changes thedelivery cross section in the second segment (3).
 12. Pump as claimed inclaim 1, wherein the first segment (1) and the second segment (3) can bemoved relative to one another.
 13. Pump as claimed in claim 1, whereinthe means (2) for producing oscillations is a part (10) which can bemoved transversely in the second section.
 14. Pump as claimed in claim1, wherein the means (2) for producing oscillations is a part (10, 23)which can be moved axially in the second segment.
 15. Pump as claimed inclaim 1, wherein the means (2) for producing oscillations annularlychanges the delivery cross section.
 16. Pump as claimed in claim 1,wherein the variable delivery cross section is bordered by an elementwhich is under stress, preferably tensile stress, with stress which canbe changed or adjusted.
 17. Pump as claimed in claim 2, wherein thesecond segment (3) has at least one membrane (9) which extends in thelengthwise direction of the pipe (4).
 18. Pump as claimed in claim 3,wherein the second segment (3) has at least one membrane (9) whichextends in the lengthwise direction of the pipe (4).
 19. Pump as claimedin claim 3, wherein the membrane (9) divides the second segment (3) ofthe pipe into partial cross sections (3 a, 3 b).
 20. Pump as claimed inclaim 4, wherein the membrane (9) divides the second segment (3) of thepipe into partial cross sections (3 a, 3 b)